You're looking down on me, aren't you?.
— Black Sperm

Black Sperm (黒い精子, Kuroi Sēshi) is one of the few Dragon monsters in the Monster Association who first appeared during the S-Class Heroes' attack on the Monster Association.


Black Sperm is a humanoid monster with a fully black body and a white face, with an antenna on top of his head.


Black Sperm seems to be very confident in his abilities and dislikes when other people "look down on him since he is a sperm looking creature". He appears to care little for the lives of humans as he was about to kill the child kidnapped by the Monster Association without remorse. As more sperm cells merge together, the newly formed cell copies become more and more arrogant. When Golden Sperm is formed, the newly formed sperm copy becomes extremely arrogant, not even caring about his other sperm copies and telling them to simply merge with him due to his superior power.


Human Monster SagaEdit

Monster Association ArcEdit

He is present at Gyoro Gyoro's speech at the Monster Association HQ and questions serving under Orochi, stating that they are only allies at the moment and are only there to crush the Hero Association. He reluctantly talks upon Gyoro Gyoro's speech about challenging Orochi for leader to himself.

After Gyoro Gyoro tries to promote Garou as one of their executives, Black Sperm shows surprise from this phenomenon and sarcastically teases Gyoro for giving Garou such lucrative offer.

Webcomic notice The following section contains Webcomic spoilers. You have been warned, manga-only readers.

Black Sperm appears when Busaiku is separated from Garou. Black Sperm chases after the kid in hopes of killing the child. Atomic Samurai steps in and manages to allow the kid to run to safety. However, Black Sperm soon overwhelms Atomic Samurai due to his ability to split into numerous versions of himself, as well as regenerate at will.

After Tatsumaki destroyed the Monster Association HQ, Black Sperm and several other Dragon level monsters emerged from the rubble to attack her. When Psykos temporarily cuts off Tatsumaki's psychic power, Black Sperm grabs Tatsumaki in a giant arm and attempts to crush her. The esper was saved by Genos, but the cyborg immediately had his arms ripped off by Black Sperm and Gums. Black Sperm and the rest of the monsters then proceed to watch Psykos play around with Tatsumaki until Genos decided to attack Fuhrer Ugly. Before Fuhrer Ugly could retaliate, Bang suddenly joins the fight and effortlessly kills two of the Monster Association's remaining members before being knocked out by Homeless Emperor. Black Sperm then takes this opportunity to knock Bomb unconscious.

Black Sperm then decides to continuously beat up Genos until King finally decided to take a stand. The remaining members of the Monster Association then try to think of a way to take on King. After King managed to buy some time against the remaining monsters, Tatsumaki began to recover and turn the tide of the battle. In an attempt to defeat her, Black Sperm fused one trillion copies of himself into the much stronger Multi-Cell Sperm. Unfortunately for Black Sperm, the newly formed sperm is effortlessly killed by Tatsumaki. Afterwards, Black Sperm sends a thousand copies of himself to perform a kamikaze attack against Tatsumaki to buy time as he takes Busaiku hostage, thus forcing the heroes to simply stand and watch as he fuses ten trillion of himself into his ultimate form, Golden Sperm. This new form proves incredibly dangerous, as Golden Sperm is able to take down Tatsumaki so fast that nobody else could even follow his movement with their eyes. However, this victory proves short-lived, as the newly mutated Garou shows up, destroying 99 of the 100 remaining copies of Black Sperm and killing Golden Sperm after a brief battle that none of the heroes could even see. Now down to only one life, Black Sperm slips away to watch the battle from afar.

Psychic Sisters ArcEdit

The next day, after encountering Saitama, Black Sperm and Overgrown Rover follow him home as pets. The two formerly dangerous monsters are currently entrusted to Butterfly DX and Chain'n'toad due to Forte losing a bet with Saitama all of a sudden, when he finally witnesses how strong Saitama is.

Abilities and PowersEdit

As a high-ranked member and a Dragon-level Mysterious Being of the Monster Association, Black Sperm is an extremely powerful being. In fact, he could be considered one of the most powerful if not the most powerful member of the Monster Association in the webcomic. Sweet Mask himself says that even if all of the S-Class Heroes fought Golden Sperm, it would still be a very difficult task to defeat him. Along with this, he was the only one besides Saitama who was able to fight against evolved Garou on equal footing, even if it was only for a few moments.

Physical AbilitiesEdit

Webcomic notice The following section contains Webcomic spoilers. You have been warned, manga-only readers.

Immense Speed and Reflexes: Black Sperm is able to dodge Atomic Samurai's slashes. Furthermore, when transformed into Golden Sperm, he blitzed an injured Tatsumaki. Even as an individual Black Sperm, he was able to keep up with Genos' immense speed.

Immense Strength: Contrary to his appearance, Black Sperm has great strength and was able to badly damage Atomic Samurai in one hit. He was also capable of lifting a huge boulder and as Golden Sperm he could fight with Garou for a few moments.

Immense Durability: Black Sperm possesses enormous durability. As Black Sperm, he was able to easily withstand all of Genos and Atomic Samurai attacks. As Golden Sperm, not even Tatsumaki's attacks phased him, although this was while Tatsumaki was significantly weakened.

Shapeshifting: Black Sperm is able to increase in size and manipulate his body shape in any way he chooses.

Regeneration and Replication: Instead of being killed, Black Sperm will only regenerate or split into even more copies of himself if he still has enough cell stock. However, there is a weakness to his regeneration: if the sperm copies decide to merge into one being, that merged sperm form will not regenerate if he is killed.

Fighting StyleEdit

Hand-to-Hand Combatant: Black Sperm mainly relies on his brute strength and his skill in close-quarters combat during battles.

Coalescence (合体, Gattai): Black Sperm permanently combines his cells to form a more powerful version of himself. The more cells that he combines, the more arrogant the created version of himself will be.
Multi-Cell Sperm Webcomic
  • Multi-cell Sperm (多細胞精子, Ta Saibō Seishi): Any number less than ten trillion of cells that combine. The strength of this form has yet to be observed as the only Multi-cell Sperm observed was quickly taken out by Tatsumaki.
Augmented Strength: Possible enhancement, but has yet to be observed.
Augmented Speed and Reflexes: Possible enhancement, but has yet to be observed.
Augmented Durability: Possible enhancement, but has yet to be observed due to being killed instantly.
  • Golden Sperm (黄金精子, Ōgon Seishi): Requires at least ten trillion cells to create. This form vastly increases his powers and he is able to defeat an injured Tatsumaki and was able to temporarily fight with evolved Garou, something none of the other S-class heroes could do.

Golden Sperm trade blows with Monster Garou

Augmented Strength: As Golden Sperm, he was powerful enough to partially penetrate through Tatsumaki's barrier as well as cause great destruction in his battle with Garou.
Augmented Speed and Reflexes: Golden Sperm is so fast that he was easily able to blitz Tatsumaki in a split of a second with no visible effort. He is also so fast that he was able to keep up with Garou's speed and none of the S-class heroes were able to see their fight.
Augmented Durability: Golden Sperm has incredible durability as he was able to take several attacks from evolved Garou and continue fighting.
Psychic Resistance: Golden Sperm is able to very effectively resist injured Tatsumaki's psychic attacks. However it has been confirmed that if she were at full power, he could lose.
Golden Sperm Webcomic

Golden Sperm Full Appearance

Kamikaze Attack (,): Black Sperm sacrifices a number of his cells to attack a target. This has been mainly used as a distraction.

Major BattlesEdit


  • "You're looking down on me, aren't you?"
  • "All heroes except Tornado, please form a line and wait for your turn to be killed."


  • ONE stated that Tatsumaki in her best shape could have beaten Golden Sperm.[1]
  • ONE stated that Golden Sperm is equal in strength to Ossan (The main protagonist from Makai no Ossan).[2]
  • He can increase his sperm stock through eating protein.
  • Black Sperm has appeared in volumes before his debut.
  • Murata is uncertain who is stronger between Orochi and Golden Sperm, but states that Orochi has superior techniques.[3]


  3. One-Punch Man Stream; 5/19/2018